Fussy eater kicked off when given the wrong starter (5)

I believe the answer is:

vegan

I'm a little stuck... Click here to teach me more about this clue!

'fussy eater' is the definition.
(someone with a particular diet)

I cannot understand how the rest of the clue works.

(Other definitions for vegan that I've seen before include "Selective consumer" , "Strict abstainer from animal products" , "An extreme vegetarian" , "Person neither eating nor using anything animal" , "Avoiding animal products" .)

I've seen this clue in The Independent.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.